Decontamination of Radioactive Cesium Released from Fukushima Daiichi Nuclear Power Plant - 13277

Peculiar binding of Cesium to the soil clay minerals remained the major obstacle for the immediate Cs-decontamination of soil and materials containing clay minerals like sludge. Experiments for the removal of Cesium from soil and ash samples from different materials were performed in the lab scale. For soil and sludge ash formed by the incineration of municipal sewage sludge, acid treatment at high temperature is effective while washing with water removed Cesium from ashes of plants or burnable garbage. Though total removal seems a difficult task, water-washing of wood-ash or garbage-ash at 40 deg. C removes >90% radiocesium, while >60% activity can be removed from soil and sludge-ash by acid washing at 95 deg. C. (authors)